TY - JOUR
T1 - Reinforcing mechanism of graphene at atomic level
T2 - Friction, crack surface adhesion and 2D geometry
AU - Chen, Shu Jian
AU - Li, Chen Yang
AU - Wang, Quan
AU - Duan, Wen Hui
PY - 2017/4/1
Y1 - 2017/4/1
N2 - Owing to its superior mechanical properties, graphene has been used to reinforce and substantially improve the strength of composite materials. Still lacking, however, is a clear understanding of graphene's reinforcing mechanism at the atomic level, especially in relation to its pull-out behavior. By molecular dynamics (MD), it is found that pull-out of graphene, different from that of micro fibers, is not governed by friction only. Rather, the pull-out force is revealed to be governed by a “crack surface adhesion” phenomenon due to unbalanced adhesion at the crack surface when graphene is not functionalized and the crack opening rate is small. Crack surface adhesion produces a constant pull-out force (about 0.2–1 N per meter width) regardless of the embedded length. There is a transition from crack surface adhesion governed pull-out to friction governed pull-out when the crack opening speed, graphene size and degree of functionalization increase. A new model is developed to integrate friction and crack surface adhesion with the 2D geometry of graphene. The new model can be used to predict the crack bridging stress for 2D graphene (or other 2D atomic thin reinforcements). The outcome of this study benefits the understanding and design of new graphene composites.
AB - Owing to its superior mechanical properties, graphene has been used to reinforce and substantially improve the strength of composite materials. Still lacking, however, is a clear understanding of graphene's reinforcing mechanism at the atomic level, especially in relation to its pull-out behavior. By molecular dynamics (MD), it is found that pull-out of graphene, different from that of micro fibers, is not governed by friction only. Rather, the pull-out force is revealed to be governed by a “crack surface adhesion” phenomenon due to unbalanced adhesion at the crack surface when graphene is not functionalized and the crack opening rate is small. Crack surface adhesion produces a constant pull-out force (about 0.2–1 N per meter width) regardless of the embedded length. There is a transition from crack surface adhesion governed pull-out to friction governed pull-out when the crack opening speed, graphene size and degree of functionalization increase. A new model is developed to integrate friction and crack surface adhesion with the 2D geometry of graphene. The new model can be used to predict the crack bridging stress for 2D graphene (or other 2D atomic thin reinforcements). The outcome of this study benefits the understanding and design of new graphene composites.
UR - http://www.scopus.com/inward/record.url?scp=85008600480&partnerID=8YFLogxK
U2 - 10.1016/j.carbon.2016.12.034
DO - 10.1016/j.carbon.2016.12.034
M3 - Article
AN - SCOPUS:85008600480
SN - 0008-6223
VL - 114
SP - 557
EP - 565
JO - Carbon
JF - Carbon
ER -